I'm interested in the Smart Cover but a little worried about how it's going to keep the screen clean. Apple says the inside is microfiber but doesn't the fact that rolling the cover into a stand mean that the inside of the cover picks up any dust/dirt on the table you're sitting it on? I hope Griffin or someone comes out with a book-style case with 2 sides and a magnetic hinge.
The best protection that I had for my iPad was a TPU case on the rear and a neoprene netbook sleeve when it was in my bag.

To make it worse, the Smart Cover isn't even stable as a stand unless you fold it with the microfiber OUT. However if you're using it as a typing stand only, you can leave the microfiber part in and it works okay.